1. Field of the Invention
The present invention relates to a rotation maintaining device capable of keeping rotation of its output shaft over a long time.
2. Description of the Related Art
Expected has been a rotational mechanism capable of retaining its rotational energy with the smallest loss to utilize it in a power generation system or other various systems.
Japanese Patent Publication No. 1996-061214A describes an example of the rotation retaining mechanism for keeping its turn as long time as possible.
This rotation retaining mechanism has a shaft of rotation, a rotor provided with radial arms and attached to the rotation shaft, long slide weights freely movable along the respective arms of the rotor, and a circular guide for eccentrically rotating the slide weights with respect to the center of the rotation shaft.
The rotation retaining mechanism described in Japanese Patent Publication No. 1996-061214A intends to turn its rotation shaft based upon the principle of leverage in which a rotational moment of the slide weight moving downwardly becomes larger than a rotational moment of the other slide weight moving upwardly, caused by decentering the rotational orbits of the slide weights with respect to the center of the rotation shaft.
Inventors of this application had been prepared and tested devices similar to the rotation retaining mechanism described in Japanese Patent Publication No. 1996-061214A in order to develop a rotation retaining device capable of keeping its rotation over a long time. However, according to such devices, it was impossible to keep the rotation for many hours.
According to the consideration of the inventors, it became apparent that, in the rotation retaining mechanism described in Japanese Patent Publication No. 1996-061214A, a rotational angle rate of the slide weights caused by the difference between the rotational moments is decreased due to the friction between the slide weights and the circular guide, and this decreasing speed of the angle rate is fast in comparison with the amount of the angle rate. Thus, such rotation retaining mechanism cannot keep the rotation for many hours.
Under these circumstances, the inventors of this application have investigated and studied to provide a new rotation retaining device capable of keeping rotation of its output shaft over a long time, by reducing the friction between members as much as possible and by keeping the difference between the rotational moments as long time as possible.